She's the ghost of the daughter of the owner of a pension.
She moved from Tokyo with her father, when he quit his job as a salary man to become the owner of a pension in the mountains. She did not like living in the countryside, so she secretly fed monkeys and made them attack the pension whenever customers would come, hoping that it would drive her father to move back to Tokyo. Eventually, they both end up dying of food poisoning, and their spirits lingered, unaware that they died.
Tamako tasked Rinne to go there as a customer, and along with Sakura, Tsubasa, Ageha and Matsugo, they tried to show happy faces to the family to help them pass on, although it was difficult to do so since this place had become wrecked over the years.